In the construction of boilers that contain a multiplicity of elongate tubes in the manner common to boiler furnaces, heat exchangers, reactors and the like, it is essential that some means provide an arrangement by which the tubes are maintained spaced apart a predetermined distance. At lower temperatures, under about 1650.degree. F, it has been customary to provide spacing strips on opposite sides of a row of tubes having overlapping tabs that are joined together between the tubes by a process of welding. While such an arrangement is suitable for use at lower temperatures, higher temperatures and severe conditions of corrosion cause weldments so made to rapidly deteriorate and crack, the strips to separate, the originally effective spacing means to come apart, and the spacing means to completely fail.
Various other aligning arrangements for tubes to be used at high temperatures and under severe conditions of corrosion have been used; however, such arrangements are invariably complicated, they require additional steps in the manufacturing and assemblying process, and they are consequently expensive to use.